[Medial opening wedge high tibial osteotomy]. / Valgisierende Tibiakopfosteotomie in öffnender Technik.

OBJECTIVE: Reduction of the load to the medial compartment in patients with medial knee osteoarthritis and varus malalignment. Unloading of the posterolateral complex in varus deformity with complex ligamentous laxity. INDICATIONS: Medial knee osteoarthritis and varus malalignment with largely intact lateral and patellofemoral joint aspect. Complex ligament insufficiency combined with varus deformity. CONTRAINDICATIONS: Substantially impaired range of motion. SURGICAL TECHNIQUE: Medial skin incision on the proximal lower leg. Preparation of the pes anserinus. Marking of the osteotomy from the deepest point of the medial metaphysis laterally ascending. Biplane osteotomy, carefully protecting the posterior neurovascular structures, with ventral completion proximal or distal to the tibial tuberosity, depending on concomitant pathologies. Angular-stable plate fixation. POSTOPERATIVE MANAGEMENT: In general, early weight bearing is possible when angular-stable plate fixation is used. Often concomitant pathologies such as accompanying cartilage regenerative therapy necessitate longer unloading. Range of motion does not need to be restricted following stand-alone osteotomy. Orthoses are recommended regularly. RESULTS: Under the correct indication, the medial opening wedge high tibial osteotomy (OW-HTO) technique can achieve good results with high patient satisfaction, despite a relatively high statistical complication rate, provided that a standardized surgical technique is used. There is a tendency for a poorer outcome in patients with a body mass index above 30 and higher stages of osteoarthritis.

Local Electrical Imaging of Tetragonal Domains and Field-Induced Ferroelectric Twin Walls in Conducting SrTiO_{3}.

We demonstrate electrical mapping of tetragonal domains and electric field-induced twin walls in SrTiO_{3} as a function of temperature and gate bias utilizing the conducting LaAlO_{3}/SrTiO_{3} interface and low-temperature scanning electron microscopy. Conducting twin walls appear below 105 K, and new twin patterns are observed after thermal cycling through the transition or on electric field gating. The nature of the twin walls is confirmed by calculating their intersection angles for different substrate orientations. Numerous walls formed when a large side- or back-gate voltage is applied are identified as field-induced ferroelectric twin walls in the paraelectric tetragonal matrix. The walls persist after switching off the electric field and on thermal cycling below 105 K. These observations point to a new type of ferroelectric functionality in SrTiO_{3}, which could be exploited together with magnetism and superconductivity in a multifunctional context.

Structural and Electronic Properties of Nitrogen-Doped Graphene.

We investigate the structural and electronic properties of nitrogen-doped epitaxial monolayer graphene and quasifreestanding monolayer graphene on 6H-SiC(0001) by the normal incidence x-ray standing wave technique and by angle-resolved photoelectron spectroscopy supported by density functional theory simulations. With the location of various nitrogen species uniquely identified, we observe that for the same doping procedure, the graphene support, consisting of substrate and interface, strongly influences the structural as well as the electronic properties of the resulting doped graphene layer. Compared to epitaxial graphene, quasifreestanding graphene is found to contain fewer nitrogen dopants. However, this lack of dopants is compensated by the proximity of nitrogen atoms at the interface that yield a similar number of charge carriers in graphene.

Evidence for superconductivity in Li-decorated monolayer graphene.

Monolayer graphene exhibits many spectacular electronic properties, with superconductivity being arguably the most notable exception. It was theoretically proposed that superconductivity might be induced by enhancing the electron-phonon coupling through the decoration of graphene with an alkali adatom superlattice [Profeta G, Calandra M, Mauri F (2012) Nat Phys 8(2):131-134]. Although experiments have shown an adatom-induced enhancement of the electron-phonon coupling, superconductivity has never been observed. Using angle-resolved photoemission spectroscopy (ARPES), we show that lithium deposited on graphene at low temperature strongly modifies the phonon density of states, leading to an enhancement of the electron-phonon coupling of up to λ ≃ 0.58. On part of the graphene-derived π*-band Fermi surface, we then observe the opening of a Δ ≃ 0.9-meV temperature-dependent pairing gap. This result suggests for the first time, to our knowledge, that Li-decorated monolayer graphene is indeed superconducting, with Tc ≃ 5.9 K.

Identification of snake arenaviruses in live boas and pythons in a zoo in Germany.

OBJECTIVE: Recent studies have described the detection and characterisation of new, snake specific arenaviruses in boas and pythons with inclusion body disease (IBD). The objective of this study was to detect arenaviral RNA in live snakes and to determine if these were associated with IBD in all cases. Samples for arenavirus detection in live animals were compared. Detected viruses were compared in order to understand their genetic variability. MATERIALS AND METHODS: Esophageal swabs and whole blood was collected from a total of 28 boas and pythons. Samples were tested for arenaviral RNA by RT-PCR. Blood smears from all animals were examined for the presence of inclusion bodies. Internal tissues from animals that died or were euthanized during the study were examined for inclusions and via RT-PCR for arenaviral RNA. All PCR products were sequenced and the genomic sequences phylogenetically analysed. RESULTS: Nine live animals were found to be arenavirus-positive. Two additional snakes tested positive following necropsy. Five new arenaviruses were detected and identified. The detected viruses were named "Boa Arenavirus Deutschland (Boa Av DE) numbers 1-4" and one virus detected in a python (Morelia viridis) was named "Python Av DE1". Results from sequence analyses revealed considerable similarities to a portion of the glycoprotein genes of recently identified boid snake arenaviruses. CONCLUSIONS: Both oral swabs and whole blood can be used for the detection of arenaviruses in snakes. In most cases, but not in all, the presence of arenaviral RNA correlated with the presence of inclusions in the tissues of infected animals. There was evidence that some animals may be able to clear arenavirus infection without development of IBD. This is the first detection of arenaviruses in live snakes. CLINICAL RELEVANCE: The detection of arenaviruses in live snakes is of importance for both disease detection and prevention and for use in quarantine situations. The findings in this study support the theory that arenaviruses are the cause of IBD, but indicate that in some cases it may be possible for animals to clear arenavirus infections without developing IBD.

[Arthroscopic treatment of arthrofibrosis after ACL reconstruction. Local and generalized arthrofibrosis]. / Arthroskopische Arthrolyse bei Arthrofibrose nach Ersatzplastik des vorderen Kreuzbandes. Lokale und generalisierte Arthrofibrose.

OBJECTIVE: Restoration of free knee motion taking into account knee extension, knee flexion, and patella mobility. INDICATIONS: Prolonged knee motion restriction after anterior cruciate ligament (ACL) reconstruction, persistent decreased patella mobility, or extension deficit. CONTRAINDICATIONS: Existing significant joint irritation or active reflex dystrophy with persistent distinctive pain syndrome. SURGICAL TECHNIQUE: Arthroscopic arthrolysis possible in most cases. Removal of adhesions in all compartments. Elimination of intraarticular cause of patella infera by removing infrapatellar scar tissue and fibrotic fat pad. In case of severe peripatellar fibrotic tissue, lateral release is useful with partial transection of lateral retinacula. In case of strong capsular contracture, additional medial release indicated to improve patella mobility. Important goal of arthrolysis: full range of knee extension. Arthrolysis for scar tissue removal in the posterior recessus through dorsomedial arthroscopic approach possible. In severe cases posteromedial arthrotomy for posterior capsule release required. Cyclops syndrome makes removal of all tissue adherent to the ACL necessary. An irregular ACL insertion or intercondylar notch stenosis may require notchplasty. Postoperative recurrence of fibrosis may require repeated arthroscopic surgery to improve mobility, such as notchplasty, osteophytes resection, scar removal, and releases. POSTOPERATIVE MANAGEMENT: Immediate postoperative pain-free physical therapy taking into account full range of extension and patella mobility. Passive exercises under traction. Lymphatic drainage. No exercising in pain throughout the entire postoperative physical therapy. Continuous passive motion treatment for 4 weeks postoperatively useful. No muscle strength or equipment training for at least 3 months postoperatively. RESULTS: Based on the observations in our working group, approximately pproximately 78% of patients develop knee osteoarthritis within 5 years.

Mass-mortality in green striped tree dragons (Japalura splendida) associated with multiple viral infections.

In spring 2011, high mortality in association with skin lesions, systemic haemorrhages and necrosis occurred in a group of green striped tree dragons (Japalura splendida) which were imported from southwestern China via Florida to Germany. Infections with various endoparasites were diagnosed in coprological examinations. Different antiparasitic and antibiotic treatments over a period of three months did not reduce the mortality rate. The remaining animals were therefore euthanased and submitted for additional testing. Predominant findings in pathological examination were granulomatous and necrotising inflammation of the skin, vacuolar tubulonephrosis of the distal renal tubules, hyperaemia and liver necrosis. Eosinophilic intranuclear and basophilic intracytoplasmic inclusion bodies were detected in the liver. Virological testing (PCR and virus isolation methods) demonstrated the presence of ranavirus, adenovirus and invertebrate iridovirus.

High responsivity GaNAsSb p-i-n photodetectors at 1.3 microm grown by radio-frequency nitrogen plasma-assisted molecular beam epitaxy.

GaNAsSb/GaAs p-i-n photo notdetectors with an intrinsic GaNAsSb photoabsorption layer grown at 350 degrees C, 400 degrees C, 440 degrees C and 480 degrees C, have been prepared using radio-frequency nitrogen plasma-assisted molecular beam epitaxy in conjunction with a valved antimony cracker source. The i-GaNAsSb photoabsorption layer contains 3.3% of nitrogen and 8% of antimony, resulting in DC photo-response up to wavelengths of 1350 nm. The device with i-GaNAsSb layer grown at 350 degrees C exhibits extremely high photoresponsivity of 12A/W at 1.3 microm. These photodetectors show characteristics which strongly suggest the presence of carrier avalanche process at reverse bias less than 5V.

[Platypnea-orthodeoxia of a 69-year old woman with a patent foramen ovale]. / Platypnoe-Orthodeoxie-Syndrom einer 69-jährigen Patientin bei offenem Foramen ovale.

Platypnea-orthodeoxia is a rare syndrome that is often associated with interatrial shunting through a patent foramen ovale (PFO) or atrial septal defect. We describe the case of a 69-year-old woman with progressive dyspnea and hypoxia when standing, which was relieved by assuming the recumbent position. After detection of a PFO by transesophageal echocardiography the diagnosis was confirmed by transthoracic echocardiography using saline contrast injection while lying supine and standing upright. This maneuver demonstrated a large right-to-left shunt through a patent foramen ovale while the patient was in a upright position and no significant shunt while being in a recumbent position. The patient showed a rapid improvement after closure of the PFO. This case demonstrates that platypnea-orthodeoxia caused by a patent foramen ovale can be easily demonstrated by the technique of contrast transthoracic echocardiography and a simple positioning maneuver.

[Coagulation disorders in tumors and hemoblastoses]. / Gerinnungstörungen bei Tumoren und Hämoblastosen.

Thromboembolic and haemorrhagic complications are not rarely seen in the course of malignant diseases. The underlying coagulation disorders were investigated by means of coagulation analysis in 61 patients with solid tumors and 60 control persons as well as 51 patients with leukemia and 50 control persons. As a cause for the thrombotic diathesis in patients with solid tumors and leukemias can be demonstrated a hypercoagulability (shortened PTT and raised factor VIII activity). In addition we found a raised level of fibrinogen, a hypofibrinolysis (prolonged euglobulin lysis time) and in increased platelet aggregation in patients with solid tumors. Predominantly bleeding complications in leukemias are caused by thrombopenia. Another reason, however, may be an activated fibrinolysis or a clot instability because of the reduction of factor XIII. Pathogenetic mechanisms, underlying the tumor induced coagulation disorders, as for example the release of tumor cell thromboplastins from malignant cells are discussed.